1. Field of the Invention
The present invention relates to an optical sensor for detecting peripheral light and a liquid crystal display device using the same, and, in particular, to an optical sensor for detecting peripheral light and a liquid crystal display device using the same capable of stably obtaining output current while minimizing a mounting space.
2. Discussion of Related Art
Various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes, have been developed. These include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display (OLED), etc.
Liquid crystal display devices have advantages of slimness, lightweight, low power consumption, etc., so that they may overcome the disadvantages of existing cathode ray tubes. Liquid crystal display devices may be mounted in mobile equipment, such as mobile phones, personal digital assistants (PDAs), etc., as well as monitors, televisions, etc., which are middle and large-sized products. Such liquid crystal displays are transparent type display devices and display desired images by controlling the amount of light transmitted through liquid crystal layers by utilizing the refractive index anisotropy of liquid crystal molecules.
In such liquid crystal display devices, a backlight radiates light with constant brightness to each pixel unit. However, even though a large amount of light is not required when a peripheral environment is dark, the power consumption of the backlight remains high due to the supply of light with constant brightness to each pixel unit. The backlight consumes 80% or more of the power consumed for operating the liquid crystal display device.
Therefore, there is a need for a method of effectively controlling the light of a backlight by utilizing an optical sensor for detecting peripheral light, and a method of improving the output characteristics of the optical sensor for detecting peripheral light to be able to effectively detect the peripheral light.